1. Field of the Invention
The present invention relates to a capstan motor for use in a VTR or the like, and also to an improvement in a bearing housing for supporting a rotating shaft of the capstan motor.
2. Description of the Related Art
FIG. 14 is a sectional view of a conventional bearing housing 1 for use with a capstan motor.
The bearing housing 1 is formed mostly by casting, especially by die casting. In general, die casting provides a high accuracy of products and almost eliminates a need of machine finishing, so that it is widely used for manufacture of such a bearing housing.
Thus, the bearing housing 1 is formed as an integral body manufactured by die casting. The bearing housing 1 has a substantially circular flange portion 2 to be fixed to a mounting board on a chassis (not shown) of a VTR or the like.
Although not shown, a flat capstan motor having a stator portion and a rotor portion is provided on a left-hand surface of the flange portion 2 as viewed in FIG. 14, and a rotating shaft extends from the rotor portion into the bearing housing 1 along a center line C1 of the bearing housing 1.
A housing body 4 extends from a right-hand surface of the flange portion 2 as viewed in FIG. 14, and has a hollow cylindrical shape so as to fixedly mount therein a pair of bearings 3 for rotatably supporting the rotating shaft.
A cylindrical wall of the housing body 4 is partially cut away to form a window-like recess 5 from which the rotating shaft is partially exposed.
The capstan motor provided with the bearing housing 1 is mounted perpendicularly to the chassis of the VTR, thereby receiving in the recess 5 a magnetic tape (not shown) traveling with its transverse direction according with a longitudinal direction of the bearing housing 1.
Accordingly, the magnetic tape is kept in contact with the rotating shaft exposed from the recess 5, thereby receiving a traveling force from rotation of the rotating shaft.
In the bearing housing 1 constructed above or the capstan motor provided with the bearing housing 1, there is a problem that a die for manufacturing the bearing housing 1 by die casting is expensive.
Further, a pinch roller (not shown) is pressed against the rotating shaft according to a traveling mode of the magnetic tape, and a pressing force of the pinch roller is applied through the bearings 3 to the elongated housing body 4.
Accordingly, there is a possibility that the capstan motor mounted so as to stand upright from the chassis may be gradually inclined as time proceeds.
To cope with this problem, it is considered to increase the strength of the bearing housing 1 by thickening the wall of the bearing housing 1. However, a material cost for the bearing housing 1 is increased by the thickening of the wall to cause an increase in manufacturing cost.
Further, since the bearing housing 1 is integrally formed by using a die, the size (depth) of the recess 5 is limited. Accordingly, when the bearing housing 1 is mounted on the chassis of the VTR in such a manner that a tape traveling path is bent about the rotating shaft, a wide space for mounting parts associated with the capstan motor is required.
Such a wide space causes a hindrance against a reduction in size of equipment in which the capstan motor is mounted.